Treatment of cellulose derivatives



Nov. 7, 1933.

J. F. BRIGGS ET AL TREATMENT OF CELLULOSE DERIVATIVES Filed Aug. 2, 1929 TOHN F- BRIGGS ROBERT P. ROBERIS )nve ntors Attorneys Patented Nov'. 7, 1933 I UNITED "STATES PATENT OFFICE 1,934,618 I TREATMENT OF CELLULOSE DERIVATIVES John FrederickBi-iggsandRobert-Pierce Roberts,

Spondon, near Derby, England, assignors to Celanesc Corporation of America, a corporation of Delaware Application August 2, 1929, Serial No. 382,907,

and in GreatBritain August 13, 1928 30 Claims.

This invention relates to the manufacture of artificial silk and other filaments or threads from solutions of cellulose acetate or other cellulose derivatives, and particularly to their manufacture by the dry or evaporative method.

It is, of course, of the utmost importance to ensure that filaments of uniform character can be produced in any desired number of cells, and that any particular type of filament, can be produced at will by varying the conditions of operation of the spinning plant. By the use of the means described in U. S. Patent No. 1,541,104, filaments and threads of high quality and uniformity are produced by controlling the amount of evaporative medium, e. g. air, passing through each cell and by enabling a uniform flow to be obtained in any desired number of cells, for. while numerous variations may be introducedin. the control and operation of the spinning plant, it has been found of particular importance to ensure regularity of the flow of evaporative medium passing through thecells of the plant. Further, while the evaporative medium maybe introduced at the top, or bottom, or elsewhere into the cell, and may be introduced already heated or nontheabovementioned requirements asto regularity of flow and uniformity of fiow as between all the cells must always be observed if uniform'filaments or threads of high quality are to be obtained, and the means described in U. S. Patent No. 1,541,104, for controlling the flow may be used for this purpose in all these cases. 7 s

Further means for controlling the spinning operation are described in U. 8.. Patent application S. No. 236,448 filed 29th November, 1927, which describes collector devices adapted to. utilize the full evaporative capacity of the evaporative medium by constraining practically the whole of it to pass through the immediate vicinity of the nozzle, these collector devices'enabling a stricter control to be exercised, over the cross-sectionof the filaments, and allowing flat, semi-flat,v or substantially rounded filaments to be obtained at will.

It has now been found that the uniformitv and character of the filaments or threads can be controlled to a degree hitherto unattainable by introducing an evaporative medium into the spinning cell in the vicinity of the spinning jet. The evaporative medium thus introduced is preferably di rected' into proximity to the filaments issuing from the jet, and it may be introduced into the cell at the level of the jet face or at some distance behind or in front of the jet face; The medium may be heated or not, as desired and may contain if desired, vapours, such ,as for example, vapours (o ms) 7 of the solvent or solvents usedin the spinning solution, though,-preferably, the evaporative medium is introduced alone into the cell.

-Any suitable device may be employed for the introduction of the evaporative medium. Thus, for example, a perforated or slotted tubular ring,

' a straight or curved perforated or-slotted pipe, a

jet or jets, or other orifice or orifices, maybe arranged at the desired level in the cell with respect to the level of the spinning jet; or nozzle.

The direction taken by or imposed on the evaporative medium introduced by the ring, tube, or

other device may be the same as that of the issuing filaments, or 'may be opposed, normal, or otherwise arranged with respect thereto, ,while the medium is with advantage applied symmetrically with respect to the bundle of filaments Thus with acircular bundle'of filaments, or series of concentric circular bundles of filaments the evaporative medium is advantageously caused to flow through a space. coaxial with the bundle, or

a flow meter and a valve, all the individual chambers or cells of .an installation being similarly provided to ensure that the same conditions as to the introduction of the medium apply to all the chambers 'or cells, for the purpose of obtain ing a uniform grade," of filaments.v In order to secure uniformity of flow of the evaporative medium in all the cells, it is important that the draw-off from the cells also be controlled in the manner'described in the above-mentioned U. S.

Patent No. 1,541,104. The draw-off from the cells and the admission of evaporative medium to the vicinity of the spinning jets may be so, controlled that the amount of medium introduced'in the vicinity of the jets can vary from a relatively small proportion of the total amount of evaporative medium to a relatively large proportion or even the total thereof. l

Pressure may be employed to effect the introduction of the mediumto the vicinity of the jets,

though the suction of the draw-ofi devices may be used to aspirate the desired-amount of, medium, particularly where the admission conduit for such medium is provided with a throat or constriction as described above.

The medium introduced in the vicinity of the jets may be heated before its introduction, and

any suitable means may be employed to impart the desired degree ,of heat thereto, but, on'the other hand, cold or comparatively cold medium may be introduced into the cell if desired.

The invention is applicable to any dry-spinning For example, it may be process or apparatus. used in connection with dry-spinning processes in which the spinning solution-is extruded downwardly into an upwardlymovingcurrentof evaporative medium, or upwardly into'a downwardly moving current, or in any other processes in which solidification of the filaments is effected by means of evaporative medium;

When the invention is employed in conjunc-' through the immediate vicinity of the filaments tion with line jets;

moving through the cell, for example, such devices may" extend across the whole width of the cell with the exception of an area substantiallyoccupiedby the' filam'entsyand may-besimilarto the devices for constraining the' evapo'rative medium topassthrough the immediate vicinity of the filaissuing' froin'the'jet or nozzle described in 'U.-;S. application SQ No. 236,448. "Further the chambers or cells may be'of the type wherein the end remote-from the'jet or nozzle is open to the *of the spinning room, or wherein a relatively large'number of jets or nozzles are arranged infea'ch chamber orce'll, as described in U. -S'. Patent-applications S. Nos. 311,213 and 311;2l4'fl1ed 8th October, 1928.

' Where the evaporative medium which "is to be introduced according to the invention is desired to contain a proportion of solvent or otherva- :the vapours maybe introduced by admixture or by passing the medium through a moistening' chamber, or by mixing it" with -'solvent-laden mediumiifor example, solvent-laden medium withdrawn-fromthclcell.

Several embodiments of the invention are illustrated-'inthe accompanying drawing with referenceito the'downward spinning of artificial filanrehtsfbut is isfto be understood that'the follow- 1 g description isgiven byway of example only,

andfis in no way'illustrative;

Rig: 1 shows a perspective view of one arrangement according to the invention, in which additio foratedor-slottedtubes; e l

I rig. 2 shows, in section, several alternative rdrmedr a perforated or slottedtubj Fig.8 shows aform of device for use in connec- 'Figfl isa section on the lined-4 of Fig. 3,-and

Fig: 5 is'a'vertical section of=a spinning cell, and illustratesmeansfor controlling the amount of 'addition'alme'dium introduced mm the cell, and

drawnofi fromthecell. H v

Referring to Fig. 1, the jets 6 arranged for he'amount of solvent laden evaporative medium downwardspinning are supported by the filterchambersfl, the upper portions of the chambers "(being shown brokenaway for sake of clearness. A tubular ring-'8 surrounds'the axis of eacli'chamber f-and a pair of rings is connected by a tube 9.

*Each ring' 8 may be at the level. of the'jet 6 or above or-below'such level.- 'I'he'supply pipe 10 .When thering 8 is arranged some distance above the level of the nozzle 6; (b) shows perforations 12 from whichevaporative medium is directed substantially radially inwardly from the ring 8, and in (c) perforations 13 direct additional medium inwardly andsomewhat downwardly from the ring 8. The forms (1)), (c), are preferred .whenithe ring 8 is at or about the level of the nozzle 6 or below the level of the nozzle 6. In-

stead of the perforations l2, 13 shown in Figs. 2 (a) and 2 (1)), slots 12 13 may be employed. ewise, a continuous slot maybe formed round the rings 8,. affording an annular passage for the evaporative mediumf By the employment of any of the above described forms of perforated or slotted ring, the evaporative medium is directed into proximity to the filaments l4 issuing from the nozzles. V

In Figs' 3 and 4, a perforated tube 15, of U' form, isconn'ected by a-pipe 16 to a supply of evaporative medium, and is so arranged with respec tea line jet 1'? that slots or perforations 18 in the two limbs ofthe tube direct the medium into the'vicinity of the filament lil issuing from the jet 17. The slots or perforations 18 may cause the evaporative medium to be directed inwardly towards the filaments or somewhat upwardly or downwardly aswell as inwards, or upwardly or downwardly parallel to the filaments. As has been described with reference to Fig; l, the tube "15 may be'arranged 'at the level of the jet 1'7,

or at some' distance above or below the jet.

In Fig. 5, a perforated or slotted ring or tube 20 is connected by a pipe '21 to a supply header 22, the header 22 serving to deliver evaporative mediunr'to any desired number of devices 20.

ring or tube, and particularly for enabling uniform amounts to "be introduced to a number of cells required to produce a uniform grade of filament, a valve 24 is inserted in the pipe 21 and is operated in'accordance with the reading of a h e "flow: meter 25, which is connected to the pipe 21. 3 al medium is' introduced by means of per- For the purpose of controlling the amount of -solvent laden evaporative medium drawn from each cell 23, and particularly for obtaining a 'umforrn draw-oil from a number of cells in which uniform filaments are to be produced simultaneously, control means such as those described in U. S. Patent No. 1,541,104 may be employed; as shown in Fig. 5. 'The evaporativc medium is drawn off by suction through a pipe 26 under the control of a valve 2'7 and passes into i a header 28. A flow meter 29 inserted in the pipe 26 between the valve 27 and the inlet 30 of the pipe'ena'bles the flow to be observed. The inlet 30 of the pipe-26 is arranged at the upper end of the cell 23'at a higher level than the jet face.

Heating of the evaporative medium introduced by 'the ring, tube, or other member may be effected, if desired, by means of heating devices arranged inside or outside the cell. For example, the connection of the ring, tube or the like to the source of evaporative medium (e. g. the pipe 10) may pass through the whole or part of the length of the cell before reaching the ring, tube, or the like.

According to the invention, uniform filaments of any required cross-section may be produced and by suitably controlling the temperature conditions in the cell, the quantity of evaporative medium passing therethrough, and the speed of the filaments, and/ or of the evaporative medium, filaments of hollow cross-section may be obtained. The invention may be applied to any type of cell or chamber for use in spinning by the dry or evaporating method, whether the cells are of relatively small or relatively great cross-section, whether circular in section or otherwise, or whether each cell contains one or other small number of jets or nozzles or a relativelylarge number of jets or nozzles. Also, where a current of evaporative medium is passed through the cell and is to be heated, such heating may be effected outsidethe cell, or inside by jackets surrounding the whole or a part of the length of the cell, by a coil or coils inside the cell, by banks or other arrangement of pipes extending through several cells, or by any other suitable means, control means being preferably provided whereby uniform or regulated variations in temperature may be effected along the height of the cell.

Filaments or threads produced according to the invention may be wound, or twisted and wound continuously with their production, for instance, by submitting them to a cap-spinning operation as described in U. *8. Patent application S. No. 615,682 filed 29th January, 1923, such operations preferably being carried out outside the cell or chamber in which the filaments or threads are produced. Further the filaments or threads may be subjected to any desired operations such as moistening, lubricating, stretching, or sizing at any suitable point in their travel to the winding, or twisting and winding devices.

While the invention is particularly applicable to the production of filaments or threads having a basis of cellulose acetate, it may also be used in the manufacture of filaments or threads from solutions containing cellulose formate, propionate or butyrate, or thiocarbamic or alkoXy-alkacyl esters of cellulose, or methyl, ethyl or benzyl cellulose, or the corresponding condensation products of cellulose and glycols or other polyhydric alcohols, or other substitution derivatives of cel* lulose that are capable of being formed 'into artificial filaments or threads by dry or'evaporative methods.

What we claim and desire to secure by Letters Patent is:

l. A process for the production of artificial filaments compris'ng extruding a spinning solution into a spinning chamber, introducing evaporative medium into the'immediate vicinity ofthe filaments substantially at the point of extrusion, and withdrawing at least part of the evaporative medium entering the chamber at a point substantially at least as near the spinning end of the chamber as the point at which said introduction of evaporative medium is effected.

2. A process for theproduction of artificial filaments compris'ng extruding a spinning solution into a spinning chamber, introducing evaporative medium into the immediate vicinity of the filaments substantially at the point of extrusion, and Withdrawing the whole of the evaporative medium entering the chamber at a point substantially at least as near the spinning end of the chamber as the point at which said introduction of evaporative medium is effected.

3. A process for the production of artificial filaments comprising extruding a spinning solution intoa spinning chamber, introducing the whole of the evaporative medium required into the immediate vicinity of the filaments substantially at the point of extrusion, and withdrawing at least part of the evaporative medium entering the chamber at a point substantially at least as near the spinning end of the chamber as the point at whichsaid introduction of evaporative medium is effected.

4. A process for the production. of artificial filaments comprising extruding a spinning solution into a spinning chamber, introducing the whole of the evaporative medium required into the immediate vicinity of the filaments substantially at the point-of extrusion, and withdrawing the whole of the evaporative medium entering the chamber. at a point substantially at least as near the spinning end or" the chamber as the'point at which said introduction of evaporative medium is effected.

5. A' process for the production of artificial filaments comprising extruding a spinning solution into a spinning chamber, introducing, from a side of said chamber, evaporative medium into the immediate vicinity of the filaments substantially at the point of extrusion, and Withdrawing at least part of the evaporative medium entering,

the chamber at a' point substantially at least as near the spinning end of thechamber as the point at which said introductionof evaporative medium is effected.

6. A process for the production of artificial filaments comprising extruding a spinning solution of a cellulose derivative intoa spinning chamber, introducing evaporative medium into the immediate vicinity of the filaments substantially at the point of extrusion, and withdrawing at least part of the evaporative medium entering the chamber at a point substantially-at least as near the spinthe spinning end of the'chamber as the point at which said introduction of evaporative medium is effected.

'8. A process for the production of artificial filaments comprising extruding a spinning solution downwardly into a spinning chamber, introducing evaporative medium into the immediate vicinity of the filaments substantially at the point of extrusion, and withdrawing at least part of the evaporative medium entering the chamber at'a point substantially at least as near the upper end of the chamber as the point at whichsaid intro duction of evaporative medium is efiected.

9. Process for the production of artificial filaments from solutions of'organic derivatives of cellulose, said process comprising extruding a spinning solution into a current of evaporative medium, causing said current to flow in a direction opposite to the direction of extrusion of the filaments and introducing additional evaporative medium into the said current in the vicinity of the point of extrusion'of the filaments.

. 1o; P'rocess'for the productionof artificialfilaments from solutions of. cellulose esters, said process comprising-extruding aspinning; solution into a' current of evaporative medium, causingsaid current to fiowin adirection. opposite to the. direction ofextrusion of the filaments and introducing heated evaporative: medium into the said: current in the-vicinity of thepoint of extrusion of the filaments.

l1. Processfor the production. of artificial filaments from solutions of.= cellulose acetate; said process comprising extruding a spinning solution into a current of evaporative medium, causing said currentto flowlin'a direction opposite to the direction:of'extrusion ofthe filaments and introducing additional evaporative; mediuminto the said current in the vicinity of the point of extrusion of' the filaments.

12. Process for the production of artificial filaments from solutions of. organic derivatives of cellulose, said process comprising extruding a spinning solution into acurent of evaporative medium, causing said. current toflow in:a direction opposite to the direction of extrusion-of the filaments, introducing additional evaporative medium into' said current in the vicinity of the point of extrusion of the filaments; and'directing the said evaporative'mediunrtowardsthe filaments. I

13. Process for the production of artificial-filamentsfrom' solutions of organic derivatives of cellulose; said process comprising extruding a spinning solution into a current of evaporative medium, causing saidcurrent to flow in a direction opposite to the direction of extrusion of the filaments, and'introducing'additional'evaporative medium intothe said current at a point in proximity to the filaments immediately after they have left the point of extrusion.

l4. Processv for the. production of artificial-filaments. from solutions of cellulose acetate, said process comprising extrudinga spinning. solution into a current of evaporative medium, causing said current to fiow ina direction opposite to the direction of extrusion; of: the filaments,.and introducing additional evaporative medium into the said current at a point in proximity to the filaments immediately after they have left the point of extrusion; and in a manner which is symmetrical with respect to the. filaments.

15. Process for'the productionof artificialfilaments from. solutions of organic. derivatives of cellulose, said process comprising extruding a spinning solution into a current of evaporative medium, causing said current to flow in a. direction opposite to the direction of extrusion of the filaments, and introducing additional evaporative medium together with aproportion of vapors of a-material which is a solvent for-the substance or" the filaments into the said current in the vicinity of the point of extrusion.

l6. Processior the production of artificial'filaments from solutions of organic derivatives'of cellulose, said processcomprising; extruding the sp nning solution downwardly into an' upwardly movingcurrent of evaporative-medium, and in-- troducing additional evaporative medium into the said current in the vicinity of the point of extrusion.

17.. Process. for the production of artificial filaments from solutions of organic derivatives of cellulose, said process comprising extruding a spinning solution into a current'of evaporative medium, causing said current to fiow in a direction opposite: to the direction of extrusion of the filaments, and introducing additionalevaporative mediumin controlledramount into thesaid currentin the vicinity of the point of extrusion of the filaments.

' 18. Process for the production'of artificial filaments from solutions of organic derivatives of cellulose, saidprocess comprising extruding a spinning, solution into a current of evaporative medium, causing saidcurrent to flow in controlled amount in a direction opposite tothe direction ofextrusion.ofthe-filaments, and introducing: additional evaporative medium into: the said current in the vicinity of the point of extrusion of the filaments.

19.- Process for the production of artificial filaments: fromisolutions of organic derivatives'of cellulose, said process comprising extruding the spinning, solution downwardly intoa current of evaporative medium flowing upwardly in controlled amount, and introducing additional evaporative medium in controlled amountrinto thei'saidacurrent' in the vicinity of the pointof extrusion.

'20. Prccessforthe production-of.artificialzfilaments from solutions of: cellulose esters, said process comprising. extruding a spinning solution downwardly into a current of evaporative medium flowing upwardly in controlled: amount, and introducing additional evaporative medium in controlled amount into the said current: in the vicinity. of the point of 'extrusionof the filaments 21. Process for the production of artificialfilaments from solutions of cellulose acetate, said process comprising extruding a spinning solution downwardly into a current of evaporative medium, flowing upwardly in'controlled amount andintroducing additional evaporative medium in controlled amount into the said current inthe vicinity of the point of extrusionof the filaments; g

22; Dry-spinning apparatus for theproduction of artificial filaments, said'apparatus comprising a spinning chamber, a spinningjetdisposed near an end of said chamber, means for introducing evaporative medium intothe-immediate vicinity of saidijet, and means for' withdrawingevaporative medium from the chamber, said means being disposed: substantially as near the spinning, end of the chamber as the-'said'introducing means;

23; Dry-spinning apparatus-for. the production of artificialzfilaments, said apparatuscomprising a spinning chamber, a spinning'jet disposed-near an: end of said chamber, meansifor introducing evaporative medium intozthe immediate vicinity of said jet, means for withdrawing. ev-aporative A mediumfrom the chamber, saidmeans'beingdisposed substantially as near the spinning end of thechamber astthe said introducing means, and means for introducing evaporative medium into the chamber at the end remote from the jet.

24:. Dry-spinning apparatus for the production of artificial filaments, said apparatus comprising a spinningchamber, a spinning jet disposed-near an end of: said chamber, meansfor introducing evapora-tive medium into the immediate vicinity of said jet, and-means for withdrawing evaporative medium from the chamber, said means being disposed at one side of the chamber. at a point substantially as near the spinning end of the chamber asthe said introducing means.

25. Dry-spinning apparatus for the production of artificial filaments, said apparatus comprising a spinning chamber, a spinning jet disposed near an: end-of said chamber, means ataside ofthe jet for introducing evaporative medium intotheimlate mediate vicinity of said jet, and means for withdrawing evaporative medium from the chamber, saidmeans being disposed substantially as near the spinning end of the chamber as the said introducing means.

26. Dry spinning apparatus for the production of artificial filaments, said apparatus comprising a spinning chamber, a spinning jet disposed in said chamber, means for causing a current of evaporative medium to pass through the said chamber in a direction opposite to the direction of extrusion of the filaments, and means for introducing additional evaporative medium into the said current in the vicinity of the jet.

27. Dry spinning apparatus for the production of artificial filaments, said apparatus comprising a spinning chamber, a spinning jet disposed in said chamber, means for causing a current of evaporative medium to pass through the said chamber in a direction opposite to the direction of extrusion of the filaments, and a perforated tubular ring adapted to introduce additional evaporative medium into the said current in the vicinity of the jet, said perforated tubular ring being symmetrically disposed with reference to the jet.

28. Dry spinning apparatus for the production of artificial filaments, comprising a spinning chamber, a spinning jet disposed in the upper end of said chamber, means for causing a current of evaporative medium to pass upwardly through the said chamber, and means for introducing additional evaporative medium into the said current in the vicinity of the spinning jet.

29. Dry spinning apparatus for the production of artificial filaments, said apparatus comprising a spinning chamber, a spinning jet disposed in said chamber, means for causing a current of evaporative medium to pass through the said chamber in a direction opposite to the direction of extrusion of the filaments, means for introducing additional evaporative medium into the said current in the vicinity of the jet and means for controlling the amount of additional evaporative medium so introduced.

30. Dry spinning apparatus for the production of artificial filaments, said apparatus comprising a spinning chamber, a spinning jet disposed in said chamber, means for causing a current of evaporative medium to pass through the said chamber in a direction opposite to the direction of extrusion of the filaments, means for controlling the amount of evaporative medium passing through the chamber, and means for introducing additional evaporative medium into the said current in the vicinity of the jet.

JOHN FREDERICK BRIGGS. ROBERT PIERCE ROBERTS. 

